Aircraft: C172
Phase of flight: Cruise
Anomaly: Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Published Material / Policy

I was relieving the Local Controller and was briefed that a traffic watch aircraft was flying a VFR Transition (per the Letter of Agreement; the Tower Transition calls for the traffic watch aircraft to climb to 2;000 feet pass over the airport; South to North; then proceed eastbound after crossing the field descend to 1;500 feet ). Since I don't spend too much time in the tower; I commented that the aircraft would turn East towards [the] highway as to check myself up on the procedure. The controller being relieved said negative; the aircraft is going North to join [another] Highway. I said I didn't think that was correct and began looking for the cheat sheet for the Tower Transition. During this time several others in the tower cab told me I was wrong that the Tower Transition turns north not east; including the supervisor who was shouting across the tower cab. After confirming for myself that the Tower Transition did indeed turn East towards [the] highway; I noticed the aircraft heading North. I asked the pilot's intentions to which he responded; 'North to join [another Highway].' I said negative that is not the Tower Transition; turn right heading 090. At this point the supervisor addressed me again from across the tower cab and said thats not how we do it; the transition is to the North. I again questioned the controller I was relieving to confirm the aircraft was flying the Tower Transition. He confirmed the aircraft was flying the Tower Transition; but really didn't know the procedure. I reiterated that the map shows the transition to the East. Again I was told I was incorrect by others in the tower including for a third time the supervisor. I then questioned the pilot who said he had never been taken East.My conclusion is that no one in the tower cab other than myself knew the correct procedure. It had been done incorrectly so long and so often that even the pilot didn't know the correct routing. Later that morning; two other supervisors were told about the situation and both said that; according to the Letter of Agreement the aircraft is to turn North (which is incorrect). I cannot begin to explain how disconcerting this made me feel trying to control traffic while everyone in the tower cab is telling me I'm doing it wrong and thats not how we do it. When in reality I was the only one who knew the correct procedure. This is not an isolated incident. Situations like this have occurred regularly at the facility. In my opinion as the Support Specialist for the past six years; the controllers are pretty much doing whatever they think will work regardless of documented procedures. And since the supervisors aren't familar enough with the procedures themselves; no one is being held accountable for their actions. My reluctance to share this with the Local Safety Counsel is because the opposition I faced on this issue and other issues in recent time comes from the controllers on the Local Safety Counsel including a NATCA officer. My recommendation is that the entire facility be given Refresher Training and those in the tower this morning be given Skill Enhancement Training covering all the Letters of Agreement and the Standard Operating Procedure as well as the reporting requirements of the Quality Assurance program. I know that the ERC does at times make recommendations to the facility. I hope it doesn't take something more serious to happen at [airport] before somebody actually does something about it. I have decided this evening that today was my last day in the tower. I simply am tired of working in the tower and always having to defend myself for doing what's right. I'm telling you this because I wish to convey to you how serious I think the situation is at [airport]. I truly believe the entire facility will benefit form the training I've suggested and I volunteer to help develop and teach the material. Please do something. An Air Traffic Control Procedures Specialist was working in the Tower for currency. The reporter cleared a VFR aircraft along a published VFR procedure route. The reporter believed the aircraft would proceed along certain highways and directions for that procedure. Other persons in the Tower including Supervisors told the reporter they were wrong regarding the direction the procedure directs the aircraft to fly. Upon review the reporter was correct and the other control personnel were incorrect. The reporter states this is a recurring issue in this Tower and recommends supplemental/refresher training for Tower Controllers.